LECTURE 11

In part 1 so next week next Tuesday. We start part 2, which is the more advanced

topics being unit coordinator. I get to start mine first. I also think it's quite

nice. We've just done the kidney to carry on with the kidney while you're doing

it and then you'll have my colleagues will come in and do their lectures on the

advanced part after the vacation. So just a bit of a disclaimer there this lecture

will cover renal disease today. Just so you're aware and

hopefully you're all okay with that.

So what I'm going to do today, well, we've covered the nephron we've gone from the

glomerulus the proximal convoluted tubule the loop of henle the distal convoluted

tubule and the collecting ducts. We've now going to bring it all back together again.

I'm going to talk a little bit about acid-base balance at the start of the lecture

just to finish that topic off as one of our final functions of the renal system.

And then I'm going to talk about renal failure because in order to understand the

renal system clearly, it's really important.

Isn't that you understand when things go wrong how they impact the rest of the body.

So there's some of the things I want to talk about and finally I'm going to just

mention the effect of aging on the kidneys because it's happening to us all just

to finish this session off.

Okay. So let's go back to our friend mr. P who we met a couple of weeks ago. So

Mr. P had a lot of problems. He had lots of signs and symptoms there and hopefully

now you're able to understand what was going on and hopefully explain why he was

feeling those

okay.

I'm going to focus today on this one metabolic acidosis. So that's one of the problems

with renal failure because the renal system isn't working as it should the kidneys

aren't able to balance acid-base balance or carry out acid-base balance. So let's

move on to acid-base balance for today. So

Our plasma pH the acidity or alkalinity of our plasma can be determined by that

equation at the top there don't expect you to learn these equations, but I think

it's helpful to understand where they've come from. So when we talk about pH we

talk about concentration of protons hydrogen ions.

It's approximately 14 and Imola. Okay, we work out pH by using that equation there,

which is the negative log of the concentration of protons and it's approximately

through 7.4.

Olaf cells like us to have that pH around seven point three five seven point four

when we have extremes of those if it changes then the body is always trying to bring

it back through using the renal system on the respiratory system to win then that

normal range.

If our pH of the plasma or interstitial fluid surrounding the cell's goes below

7.35 then we call it acidosis or if the talking about the plasma is acidemia if

it goes above 7.45 we would suggest it was alkalosis or Alkali Mia which means change

in the blood.

The problem is we've got enzymes in the body. As you know, very sensitive to changes

in PH on their environment. If our enzyme activity changes that has dropped quite

dramatic effects on body function and also by altering the pH by altering the hydrogen

ion concentration. We can also cause problems with other ions. For example, potassium

can also vary and also sodium

So, how do we regulate PH? Well, we producing protons all the time in the body.

One of the ways we're producing them is through cellular respiration.

So when we have cell metabolism, we metabolize within the cell during cellular respiration

and we produce carbon dioxide as you hopefully know by now carbon dioxide combines

with water to produce carbonic acid, which is an unstable volatile acid. This can

dissociate two protons and bicarbonate ions.

If we have more carbon dioxide in the plasma or in the interstitial fluid, it becomes

more acidic if we have more bicarbonate it becomes more alkaline.

Okay, if we lose more carbon dioxide, this can also lead to alkalinity.

So in the body were always trying to balance it again. This is really basic. Hopefully

it makes sense to you though. So we've got lots of chemical buffering systems. One

of the main ones that I keep harping on about is the Carbonic anhydrase that's really

important. And I think that's probably the most crucial buffering system. We have

within the renal system that allows us to buffer and maintain acid-base balance.

You've heard about the respiratory system in body systems one. So the respiratory

system is responsible for getting rid of the carbon dioxide. The renal system is

involved in conserving bicarbonate so maintaining and reabsorbing bicarbonate and

also excreting protons. So the three things together will help with our acid-base

balance.

So kept saying at the mall in the most important buffering systems in the body is

the Carbonic anhydrase buffering system as I've heard up here. Remember I talked

about the different types of Carbonic anhydrase in the nephron. We've got two types.

We've got the type to which is a cytoplasmic found inside most of the cells and

then we've got the type for which was the membrane bound that we found certainly

in the Lumen attach. The proximal convoluted tubule cells.

So Carbonic anhydrase have said before water and carbon dioxide forms carbonic acid

which breaks down if we've got a lot of protons. It drives the equation this way

to produce more carbon dioxide, which can then be breathed out.

if we've got

Less protons or less bicarbonate then the reaction can go this way. We can convert

the carbon dioxide that we breathe. We're producing through metabolism with water

to produce these to keep the balance going. Okay, so it can move either way is a

reversible reaction.

I wouldn't be a physiologist if I didn't mention a lovely equation, but again, I

don't expect you to know this off by heart. I just want you to appreciate that.

There's a relationship between carbon dioxide bicarbonate and pH and really it's

relating to that equation that we've just seen but we have famous physiologists

Henderson and hustle back who decided to work out this relationship and this is

where it comes from. So the pH of a solution

Can be determined by looking at the pka which is a dissociation constant, which

is about six point one and the positive plus the log of the concentration there

of the base over concentration of the protonated acid when we're talking about by

carbon and carbon dioxide here. You can see that you can substitute those in there.

And so you've got the concentration of bicarbonate over the concentration of carbon

dioxide as this is a gas we have to put in their solubility coefficient. So that

would be point zero three.

concentration of carbon dioxide

so that's really just describing the relationship between those and that's why we

can associate changes in carbon, dioxide and bicarbonate to alter pH.

So this slide just summarizes changes in acid and base balance, and I'm going to

just talk you through now with some examples.

What happens and why so we've got our normal range as I said before for Point 7.35

to 7.45 bodies always trying to maintain this if it falls below we get acidosis

if it goes above we get alkalosis. So if we got acidosis we can get two types of

acidosis. We can have metabolic acidosis and we can have respiratory acidosis.

metabolic acidosis can occur when the concentration of bicarbonate ions Falls okay,

or when the concentration of protons increases

so we can have metabolic acidosis if we've got somebody who has got for example,

undiagnosed diabetes mellitus.

So in that sense, they're probably producing ketones which can be acidic which can

cause ketoacidosis.

Or if you've got somebody who's got renal failure and they can't excrete the protons.

So the proton levels also increase and they can't reabsorb bicarbonate.

So renal failure or diabetes mellitus that some treated can also type one can also

cause this you may have heard in body systems, but we can get respiratory acidosis

when you can't get rid of the carbon dioxide. So if you've got a respiratory issue,

so for example, you've got COPD or chronic bronchial asthma you can't get rid of

that excess carbon dioxide. So it starts to build up in the plasma and therefore

the

individual have respiratory acidosis.

Metabolic alkalosis occurs when we either have an increase in the amount of bicarbonate.

So if you ingest large amounts of bicarbonate or if you're vomiting

if you're losing a lot of acid because you vomiting and losing a lot of hydrochloric

acid that way that can also cause problems with metabolic alkalosis.

And finally respiratory alkalosis can occur if you're getting rid of too much carbon

dioxide. So if you're hyperventilating which can be seen some individuals your breathing

off too much carbon dioxide, then the pH of your plasma will increase and you'll

have alkalosis. So it's really nice if you can explain what's happening in these

different conditions and give me an example of when it might occur.

So what does the kidney do well when you're in those situations of respiratory or

metabolic alkalosis or acidosis the kidney works with the respiratory system to

try and compensate. So if somebody's in metabolic acidosis, then the respiratory

system will try and compensate and your breathing rate will change to try and get

rid of that excess acid. So the breathing rate will increase to try and get rid

of the excess carbon dioxide to drive the carbonic acid equation the other way so

that it balances out.

Doubt the same as if you've got respiratory alkalosis or acidosis the kidneys will

then adapt to try and either reabsorb more bicarbonate or excrete more protons again

to balance out the pH. So the two tests to systems work really closely together.

This is where the exchange happens in the kidney. So the proximal convoluted tubule

plays an important role in secreting protons usually in exchange for sodium.

We've got reabsorption of chloride chloride and bicarbonate ions, the chloride helps

with the bicarbonate reabsorption. They're all the sodium. We can also excrete ammonia

Minds which helped generate bicarbonate and I'll talk about that in a moment.

In the collecting duct. We also get some secretion of protons. We can also get some

further reabsorption of bicarbonate and we also get some excretion of the dihydrogen

phosphate ions, which I'll explain in a diagram just a bit further on how that can

help generate bicarbonate as well. Okay?

So thing to remember if you're ever asked how the kidney can control acid-base balance

and how it can excrete protons. It does it in three ways and I'm going to talk through

each one of those now, we have a Carbonic anhydrase very important. We have a phosphate

buffering system, which is dihydrogen phosphate. I've just mentioned and we have

the ammonia ammonium buffering which utilizes byproducts of protein metabolism.

To produce ammonium which can then be excreted.

So let me talk through them. Now. I've put them into diagrammatic form. I hope that

helps because I find it easier to see rather than to try and remember a list. So

inside our cell there's a proximal convoluted tubule cell. Hopefully now you're

all aware that the certain Transporters that you'd always put on there. We've always

got a sodium potassium atpase on the basolateral membrane because that's the active

transport That's essential for the driving force to allow sodium to enter the cell.

Okay keeps the concentration of sodium.

Diem inside the cell low. So always stick one of those. Um

inside the proximal convoluted tubule cell we have Carbonic anhydrase to we also

have Carbonic anhydrase for

which you know about already.

We've got Transporters there. So the sodium hydrogen exchanger. We've also got hydrogen

pump there and we've also got sodium bicarbonate reabsorption there as well and

the basolateral membrane. So you understand the Carbonic anhydrase equation. Hopefully

by now. This is happening inside the cells all the time and because of that we can

either produce water and carbon dioxide or we can produce bicarbonate and protons

reversible reaction.

The bicarbonate ions can be reabsorbed along with sodium. So we get bicarbonate

reabsorption and the protons can be then it's secreted back out into the Lumen where

they can either be excreted or they can combine with bicarbonate ions that are already

in the filtrate to form carbonic acid to then form water and carbon dioxide water

can then be excreted in the urine carbon? Dioxide can actually be reabsorbed through

some of the aquaporins.

Okay, so come down so I can actually pass the membrane through aquaporins.

So you can see hopefully how this going on all the time can help provide a source

of bicarbonate or protons if required.

Yeah, it does that make sense.

Okay.

And I've given you the types of Transporters there as well.

So that's bicarbonate reabsorption. We can also have phosphate buffering now phosphate

buffering again. Look bicarbonate is still there with protons still there with company

can hide raised it's still here as well. But this occurs in many of the cells in

the nephron so because we've got this going on in all the cells we can always combine

and form protons and bicarbonate ions. So again, it's similar.

Similar process. The only difference here is using the phosphate buffering system

is in the filtrate. We can get disodium hydrogen phosphate which can dissociate

quite easily to free up protons. So if we need protons

or protons are readily available because this has been activated they can recombine

to produce sodium dihydrogen phosphate and that's salt that's quite stable. And

that's one way that hydrogen ions can be excreted.

So by protons forming other compounds they can actually be excreted quite readily

in the urine, okay?

And finally the ammonium Ian. So again similar setup with Transporters same ones

as we had on the previous again. This is happening in the proximal convoluted tubule

as well. As other areas. The only difference with this slide is we've got metabolism

of some of the amino acids example of got there is glutamine. So when they metabolize

they can produce bicarbonate ions as a by-product which can then be reabsorbed or

they can produce ammonia.

Ammonia here can actually be it can cross the membrane again utilizing some of the

pores but ammonia can actually be awesome of the urea Transporters. We can actually

get movement of your ammonia into the filtrate. Once it's in the filtrate. It can

mop up some of those free protons to produce the ammonium iron the nh4 plus the

ammonium iron is impermeable to the apical membrane. So once the ammonium ions been

produced

And it won't dissociate and it's another way. That protons can be excreted in the

urine.

Okay, so if you remember those three processes, hopefully.

That makes sense to you.

So just as a summary kidneys regulates acid-base balance by excreting protons in

the urine and you can sound with the three buffering systems. Hopefully, you could

even draw me a cell of that if need be and they also absorb involved in the reabsorption

of bicarbonate.

They work alongside the kidneys work alongside the respiratory system as the lungs

get rid of the carbon dioxide. So if one is affected the other one will compensate

and it's always good to remember that.

Okay, that's acid-base balance in a nutshell. So let's go back to mr. P. So when

you met mr. P you found out he had all these problems and in that first renal lecture.

I talked about him having chronic renal failure. Okay. What I want to do now is

talk you through what happens in renal failure and some of the possible treatments

for it.

So at the moment, there's about three million people in the UK that are at risk

of chronic kidney disease.

I'm going to show you some statistics on how many people are actually affected.

one in 10 they reckon we'll have

Chronic, kidney disease at some point in their lives. So if you think that's probably

20 odd people here's at least two people in this room will have it.

Looking at statistics you may know of people who have got renal problems. I certainly

know a lot maybe because of the field of men but I do know a lot of people friends

and family who have got chronic renal disease and as you get older you see more

so there's about three million people in the UK that being treated.

The worrying thing is about a million to about third of those don't know they've

got chronic renal disease. So remember when I said right at the beginning that you

can actually survive quite well with a high percentage of the nephrons not functioning.

So you wouldn't necessarily know that you had chronic renal disease unless you get

to the point where things start to go wrong.

One in five people admitted to a knee have acute kidney injury and the major cause

of that is dehydration or fluid loss.

40 to 45,000 people die each year from chronic kidney disease 3000 renal transplants

each year, but we require a lot more than that. So hopefully today I can talk you

through some of the treatments and some of the approaches.

So kidney disease who is affected who's most at risk? Well diabetes is the biggest

issue. So you're all fully aware of diabetes mellitus type 1 and type 2 diabetes

is the major cause of chronic renal disease.

Turn off million diabetics in the UK its climbing. The main problem is the hyperglycemia

damages the blood vessels the nephron as you now know has lots of capillaries the

glomerulus the peritubular capillaries surrounding and the high glucose if untreated

can cause problems and damage which is irreversible and it leads to ischemia eventually

and cell death.

Hypertension is another big contributor again hypertension is a silent killer. You

don't necessarily know. You've got it. You can be asymptomatic and your blood pressure

can be high for years. But all the time it's causing damage as the pressures increasing

through the nephrons remember that the afferent and efferent arterioles are trying

to control that but if your blood pressure is so high you're going to be causing

vascular damage.

Also kidney cancers the numbers of those are also increasing at the moment and I've

given you some stats there.

So I thought it was quite interesting to look at who's most at risk of renal failure

and there are

some race considerations some communities are more at risk. Also, wait appears to

play a role as well. But if you think about it, there's often an increase in prevalence

of type 2 diabetes within certain communities and again that can be attributed to

to race.

But wait as well with obesity. It tends to be that patients that are more obese

tend to suffer or could suffer from type 2 diabetes. So the link still there. So

actually we think it's about type 2 diabetes, which is the contributing factor here.

We don't understand the genetic background to chronic renal disease. There are some

genetic considerations, but certainly it looks like there are three main factors

that could contribute. So I think it's looking at those and appreciating that we

have multiple risk factors.

Okay. So when do we get renal failure? There are two types of renal failure. We

have acute kidney failure acute renal failure that can be caused by quite rapid

loss of function. Now, I talked about blood pressure changes if your blood pressure

Falls 10 millimeter mercury remember that from the first lecture

The systems in the nephron are trying to control that but if your blood pressure

drops dramatically through loss of blood extreme dehydration, the kidneys aren't

going to be able to compensate for that and that's when you're going to acute renal

failure. It can also happen through toxic injury alcohol drugs. There's some recent

evidence that NSAIDs or non-steroidal anti-inflammatory drugs can cause problems

of renal damage. Also alcohol things like kidney stones, kidney.

Is they can all cause problems?

We also have some hereditary diseases. So chronic renal failure can happen over

time as we age but it can also and it can be a contribution of some of these things

toxic injury over time. But chronic renal failure tends to be related to a hereditary

disease such as polycystic kidney disease and this is an example of person with

polycystic kidney disease and you can see that what happens is that they have these

large fluid-filled cysts that take over the structures within the kidney.

There's also glomerular disease where you get problems with the glomerulus and the

filtering apparatus of the kidneys.

So how do we test if someone's kidneys are functioning? Well, we can use your analysis

and non-invasive method what this does is it can detect blood and protein in the

urine. So it's a really quick urine sample user Clinic stick and we can detect protein

in the urine. We shouldn't have much protein in my urine at all and high protein

in the urine is usually an indicator of renal damage or renal failure.

All the things you can measure to monitor renal function is as you've heard of creatinine

we talked about in that first lecture and also Southeast in see also serum creatinine.

So if you take a blood sample in the serum creatinine is high that suggests that

your kidneys aren't clearing it. And therefore you've got problems with your renal

function and you can also do something called the bun or blood urea nitrogen levels,

which is another test that you may hear about.

So let's talk about grading kidney disease where I talked about GFR changes right

at the beginning and how we can use those to monitor renal function.

As I said this put up there a quote from the Mayo Clinic, you know many people don't

know that they've got kidney disease until they get to a point where they only got

approximately 25% of their nephrons working as they should.

The normal GFR is between 90 and 100 mils per minute. And when I gave you examples

in the first lecture, I talked about men being approximately 125 mils per minute

women being a bit less at 150 mils per minute. It's round about that range between

90 and 100 40 your clusters having chronic kidney disease if you GFR Falls below

60 Mills for more than three months. So sometimes if people have got temporary renal

issues, you can see a dip in GFR and then it picks up.

Again, so if they've got a kidney infection sometimes glomerulonephritis can cause

problems, but you can see a slight dip in GFR but it can pick up again. So that's

why you monitor it for more than 3 months.

So we can stage renal failure and it goes from stage one down to Stage 5. So stage

1 will be when your GFR is below 90. Okay, and that's for both males and females

over a period of time. It progresses as the GFR starts to fall and it's only when

we get to GFR being less than 15 that we would say 50 mils per minute that we would

say, then you're in what we call Stage 5 which used to be known.

Known as end-stage renal disease that term isn't used as much anymore because that

would seem to be quite negative. Whereas now you Sensei Stage 5 you're living with

renal disease, okay.

But that means you've gone from almost a hundred percent function down to 15% before

it gets to the point where you need some intervention until that point. You can

survive reasonably well.

Okay. So what I want to do now is go through some of the functions of the kidney.

And what we want to do is look at how renal failure affects the different systems

in the body.

So remind ourselves regulation of osmolality fluid volume, we are happy with that

electrolyte balance acid-base balance. We know about formation of urine or we excrete

toxins will talk more about this next week and we know about hormones. So a writer

a poet in is produced by the kidneys stimulates the bone marrow to produce red blood

cells. And also we appreciate now the running engine tencent aldosterone system

fits me and be metabolism not going to talk much about the advanced Endocrinology

unit in year 3 Focus.

Is all about this, okay, but the kidneys are involved in vitamin D metabolism and

the activating the vitamin D. So patients with renal problems can have problems

with calcium balance because of that as well.

Okay, so let's look at the systems in the body. Hopefully you're all familiar with

them and let's talk through now how renal failure affects these.

Okay. So if you've got problems with your kidneys your in renal failure chronic

renal failure, you are no longer able to control your fluid levels. If that's the

case your blood pressure will increase it's one of the signs of renal problems is

hypertension.

Secondary hypertension is usually caused by changes in renal function. If you increase

your BP, you're then going to contribute to more renal damage because hypertension

can also escalate renal problems.

If you've got so much sodium and water re-absorption or attention. You're also going

to find that you've probably got a Dima. So you've got swelling in your ankles swelling

in your wrists. You may also find you've got a demon within the pulmonary system

as the interstitial fluid there becomes increased that's going to lead to breathing

difficulties and that can be one of the problems with people in renal failure. They

find they can't get the breath. They're also potentially with metabolic acidosis.

Going to put more pressure on the respiratory system, which can cause problems as

well.

If you can't balance your potassium levels you got hyperkalemia, then that can lead

to cardiac arrhythmias eventually into cardiac arrest. It's really important. You

try and balance potassium levels. If you can't producer I threw up waiting then

these are all going to affect the cardiovascular system because you're not going

to produce the right number of red blood cells red blood cells. You have a likely

not to contain adequate hemoglobin. You're going to be anemic if you're anemic that's

going to cause your breathing rate change.

He's trying to get more oxygen then. If you've got pulmonary edema, and you're trying

to cope with metabolic acidosis your respiratory systems under quite a lot of pressure.

If you've got damage to the filtration apparatus if you've got something like polycystic

kidney disease, you may also find that you might get blood in urine as you have

bursts or there's damage to the glomeruli. They're also because of problems with

urea levels, you can get impaired platelet function which can lead to bruising frequent

nosebleeds.

Talked about metabolic acidosis there. So if you're unable to excrete the protons,

then that puts more pressure on the respiratory system and that can cause labored

breathing.

If you've got changes in potassium levels that can also have issues with your neurons

you tend to get peripheral neuropathy, which is what we said Mr. P hands are tingling

in your fingers and toes it can also cause Central problems such as lethargy tiredness

and confusion.

It can also cause problems with muscular function so you can get twitching you can

get cramps as a really big problem issues there.

Bone pain bone resorption so you can get calcium deposits and places. We don't normally

get them.

Hypokalemia, so low calcium levels or high phosphate levels, which is also a big

problem can cause those cramps that are talked about in this is really common, especially

at night in renal patients.

If you've got a buildup of your rear and other toxic components in your plasma that

can lead to anorexia. Anorexia here is talking about the feeling of no appetite

it can cause nausea and vomiting nausea and vomiting can also contribute to acid

base problems.

Endocrine yet writer a poet enough mentioned vitamin D have mentioned renin-angiotensin

systems disrupted lead to problems with blood pressure and not that you be concerned

about it. But also you can also have problems because our Doster owns disrupted

you can also have problems with some of the sex hormones which would affect your

fertility.

Text on the skin because of the build-up of urea and You remake toxins you tend

to get a yellow tinge to your skin. The itching that I talked about is begin because

of the build-up of those metabolic byproducts can't excrete them. You also have

problems that with platelet function get bruising you look very pale because you're

anemic so overall not looking good.

so that's some of the effects the general effects on the body that renal failure

can have says a lot of things that you probably haven't thought about that renal

patients have to contend with

So what's the best thing to do? How can we treat it? Well, one of the best things

to do is to try and control blood pressure because the kidney function of controlling

fluid and electrolyte balance is disrupted. If you can try and control blood pressure,

you're trying to limit the amount of damage that's continuing to happen within the

renal system.

So people in early stages stages one two, and three ideally you want to try and

maintain their blood pressure with medication to within approximate range of 130

over 85 at the later stages. You try and keep it even lower to try and balance and

reduce damage.

What is exciting is the one of the Annie antihypertensive drugs and attending to

converting enzyme inhibitors?

Have been shown to be really effective in reducing blood pressure. But also have

shown to have a protective effect to the some studies that have shown they've actually

have some renal protective effects, which is really exciting as you're doing two

things with balancing blood pressure. Renal patients also have to control their

diet as they need to ensure that they limit the amount of urea so they may need

to reduce the amount of protein in the diet. They will also have to limit the amount

of phosphorus in the diet's

And you'll be amazed at what food stuffs contain phosphorus and they may also need

to limit their sodium intake. Okay, because that also contributes to blood pressure

increases in salt sensitive individuals.

So what are the main treatments for?

people who suffer from chronic renal disease

two main ones that you might have heard of a hemodialysis and peritoneal dialysis

and ideally or renal patients awaiting for transplantation.

So I'll briefly describe hemodialysis. We all heard of this before.

Yeah, no. Okay. So this is an artificial way of filtering the blood hemodialysis

is

Doable it works. It keeps patients alive. It's not perfect and I'll explain why

in a moment, but the idea is so renal patients. First of all, if you go on dialysis,

you need to have usually a fistula put in so what the fistula does is on the forearm,

they will connect a vein to an artery. Okay, so it's not operation quite a minor

operation and they do it in the forearm and what it does is it means that the vein

the

Rules of the vein that are usually very thin will start to thicken so you'll have

this operation done usually after about three months.

They'll keep monitor it and hopefully they'll be able to see that the vein walls

have thickened then when you go for dialysis, you have to have cannulas put in and

you'll have one that will connect you to dialysis machine. So you have a venous

line and arterial line. And the reason you have that fish to the put in is because

the vein is quite delicate very thin-walled and if you don't have that done and

it doesn't thicken having this done three times a week, you're going to rupture

that vein.

Okay, so they have to do this and it's been shown to be quite successful.

So you have a fistula put in?

You're connected very cannula. It draws the fluid your blood from the line here.

Venous line and then it returns here. So taken out here through the arterial line

under pressure and returns through the venous line. You've got semi permeable membrane

here. So as your blood passes through you can get water and electrolytes removed.

There's no mixing of the two fluids. You just have your blood then pumped back in

again. So you have to be attached to the sheen machine for about 3 to 5 hours.

It's really good because you can stay alive on it and it keeps a lot of renal patients

alive. The problem I said there is it takes three to five hours usually near a five

by the time you get to the hospital you get on so you have to wait get on to the

dialysis machine you're on it for up to 5 hours and then obviously got to make your

way home.

There are several clinics around most hospitals do it. But again, if you live quite

a way from hospital, you've got to do that Journey three times a week and have to

do it up to five hours at a time. It takes 15 hours out of your week. Sounds like

having a part-time job.

Very difficult for renal patients to carry on with normal life try and balance this

and fit this in usually have regular days. So they just have to work the life around

it not ideal because it doesn't provide a writer a poet in so normally patients

have to have a writer a poet and injections as well doesn't always control calcium's

then might have to take calcium supplements and also phosphate binding medication

to absorb the phosphates that stops that increasing and it doesn't completely remove

the urea

There is another type of dialysis that can be done which is called peritoneal dialysis.

And this one is where you use your peritoneal cavity. So I think this is absolutely

ingenious that you have a cannula put into your abdomen and your utilizing the semi

permeable membrane function of your peritoneal membrane to allow for dialysis really

within your peritoneum.

So what happens is they put their desolate fluid into your abdomen? Okay, it stays

there and then over the day there's exchange of electrolytes and fluid and then

it's just drained off later.

The good things are this is a much slower process. It means you can carry on with

your daily life. There are different types of it now and the continuous one you

can do at home and that can be done reasonably quickly, or you can have a longer

version which can be done overnight.

The main problem with it is it's not suitable for all patients patients with something

like polycystic. Kidney won't be able to have it because of the enlarged kidneys

in the abdomen and also it's not ideal for everybody to have it done at home. Some

people prefer to have the hospital-based dialysis.

If you're interested, there's a lovely section on there the physiological Society

had the history of dialysis, which they put together a few years ago. And the main

problem with it is infection. So if you get problems if you get an infection within

your peritoneum yet peritonitis, which is extremely painful.

And if it's extremely painful you won't be able to have dialysis that way so you'll

have to revert back to human Dallas.

I've just put this slide in for interest because obviously kidney transplantation

is the optimum.

But history with it, I like looking at the history of these things, but I just wanted

to show you that the UK survival rate from having a transplant either from a cadaver

for somebody who has obviously donated afterlife.

Is not as good as having a live donor, usually a kidney transplant last up to 15

years and then they'd have to have a second transplant after that.

So what do they do when they transplant a kidney? Well, usually the leave your kidneys

in place and the third kidney is then placed lower down in the abdomen you have

a renal vein here will join to the iliac vein in the leg and the renal artery were

joined to the iliac artery.

Usually takes a little while for the kidney to wake up off known as it's sleeping

time. And once you start the perfusion the kidney will change color and after a

few days normally you can see renal function resumed life-changing operation obviously

giving life to people that have a very difficult time with chronic renal failure.

Just mention there that you're in passes out the ureter so obviously have to join

the new ureter to the bladder.

Okay considerations here then so what if I can show a little video the problem is

this requires donors?

Most of the donors that come forward a marginal donors which means their older patients.

Usually they've got reduced renal function.

The other problems are rejection patients that have a transplant have to take anti-rejection

drugs for Life the immunosuppressive drugs. They have to take have other health

risks as well that I've put there.

So in about 70 years since the first renal transplant first transplantation has

made dramatic improvements still lots of improvements that can be done.

Let's just share with you. What happened when everybody else was in lockdown? This

has been going through Parliament for a few years, but in 2019 said that the numbers

there were quite High I think was 2017. It was first presented to Parliament, but

our English law changed in 2024 donors. It was called Max and Cara's law and it

was because Max was a nine year old little boy who received a heart transplant from

Kira who unfortunately passed away.

So the two families came together and decided to give the law their names so max

is now doing very well. The new law is that you opt everybody's opted in and you

have to physically opt out if you don't want to be an organ transplant donor, which

I think is fantastic because it gives them that flexibility and hopefully makes

many organs as we age even from 20 years. So most of you aren't too far up there

you'll notice that

at the change in size of your kidneys are blood supply to the kidneys will start

to change as we get older as we live our lives. We have arterial damage atherosclerosis

again, hypertension all those sort of things can alter.

The number of nephrons are functioning will decline our ability to concentrate urine

will Decline and our responsiveness to ADH and aldosterone would decline as well

our calcium metabolism abilities. We've also got greater risks of some diseases.

So lots of things can have a list of important which I hope you've enjoyed learning

about the renal system. I look forward to seeing you next week when we start part

to to look in a bit more depth about some of the research that supports